Commit Graph

576 Commits

Author SHA1 Message Date
Reid Spencer
c8a1fcdb48 Remove unused header file.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13750 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-25 08:51:36 +00:00
Reid Spencer
3f0635e012 Make this pass simply invoke SymbolTable::strip().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13749 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-25 08:51:25 +00:00
Chris Lattner
3c6a0d4ae2 Implement InstCombine:shift.ll:test16, which turns (X >> C1) & C2 != C3
into (X & (C2 << C1)) != (C3 << C1), where the shift may be either left or
right and the compare may be any one.

This triggers 1546 times in 176.gcc alone, as it is a common pattern that
occurs for bitfield accesses.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13740 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-25 06:32:08 +00:00
Chris Lattner
a710ddc9c4 Implement instcombine/cast.ll:test16:
Canonicalize cast X to bool into a setne instruction


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13736 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-25 04:29:21 +00:00
Chris Lattner
f52988a92d Spelling people's names right is kinda important
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13702 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-23 21:27:29 +00:00
Chris Lattner
2741c97104 Adjust to the changes in the AliasSetTracker interface
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13690 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-23 21:20:19 +00:00
Chris Lattner
057f78ab4e Add support for replacement of formal arguments with simpler expressions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13689 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-23 21:19:55 +00:00
Chris Lattner
08005dfdc9 Implement the -lowergc pass which is used by code generators (like the CBE)
that do not have builtin support for garbage collection.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13688 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-23 21:19:22 +00:00
Chris Lattner
fa28bb4601 This was not meant to be committed
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13565 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-13 20:56:34 +00:00
Chris Lattner
82fec4e31d Fix a nasty bug that caused us to unroll EXTREMELY large loops due to overflow
in the size calculation.

This is not something you want to see:
Loop Unroll: F[main] Loop %no_exit Loop Size = 2 Trip Count = 2147483648 - UNROLLING!

The problem was that 2*2147483648 == 0.

Now we get:
Loop Unroll: F[main] Loop %no_exit Loop Size = 2 Trip Count = 2147483648 - TOO LARGE: 4294967296>100

Thanks to some anonymous person playing with the demo page that repeatedly
caused zion to go into swapping land.  That's one way to ensure you'll get
a quick bugfix.  :)

Testcase here: Transforms/LoopUnroll/2004-05-13-DontUnrollTooMuch.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13564 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-13 20:43:31 +00:00
Chris Lattner
be97b4e9ab Fix stupid bug in my checkin yesterday
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13429 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-08 22:41:42 +00:00
Chris Lattner
620ce14666 Implement folding of GEP's like:
%tmp.0 = getelementptr [50 x sbyte]* %ar, uint 0, int 5         ; <sbyte*> [#uses=2]
        %tmp.7 = getelementptr sbyte* %tmp.0, int 8             ; <sbyte*> [#uses=1]

together.  This patch actually allows us to simplify and generalize the code.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13415 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-07 22:09:22 +00:00
Chris Lattner
546516c3c0 Fix PR336: The instcombine pass asserts when visiting load instruction
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13400 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-07 15:35:56 +00:00
Chris Lattner
b9110c61fb Do not mark instructions in unreachable sections of the function as live.
This fixes PR332 and ADCE/2004-05-04-UnreachableBlock.llx


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13349 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-04 17:00:46 +00:00
Chris Lattner
32ed46b36e Minor efficiency tweak, suggested by Patrick Meredith
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13341 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-04 15:19:33 +00:00
Chris Lattner
00d513182d Make sure to reprocess instructions used by deleted instructions to avoid
missing opportunities for combination.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13309 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-01 23:27:23 +00:00
Chris Lattner
216d4d85fd Make sure the instruction combiner doesn't lose track of instructions
when replacing them, missing the opportunity to do simplifications


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13308 91177308-0d34-0410-b5e6-96231b3b80d8
2004-05-01 23:19:52 +00:00
Chris Lattner
c1526a9da1 Fix a major pessimization in the instcombiner. If an allocation instruction
is only used by a cast, and the casted type is the same size as the original
allocation, it would eliminate the cast by folding it into the allocation.

Unfortunately, it was placing the new allocation instruction right before
the cast, which could pull (for example) alloca instructions into the body
of a function.  This turns statically allocatable allocas into expensive
dynamically allocated allocas, which is bad bad bad.

This fixes the problem by placing the new allocation instruction at the same
place the old one was, duh. :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13289 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-30 04:37:52 +00:00
Chris Lattner
6ffe551f65 Changes to fix up the inst_iterator to pass to boost iterator checks. This
patch was graciously contributed by Vladimir Prus.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13185 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-27 15:13:33 +00:00
Chris Lattner
83a2e6e4a1 Instcombine X/-1 --> 0-X
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13172 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-26 14:01:59 +00:00
Chris Lattner
4a7553e2da Move the scev expansion code into this pass, where it belongs. There is
still room for cleanup, but at least the code modification is out of the
analysis now.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13135 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-23 21:29:48 +00:00
Chris Lattner
b4782d13d1 Disable a previous patch that was causing indvars to loop infinitely :(
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13108 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-22 15:12:36 +00:00
Chris Lattner
fcb81f5f4c Fix an extremely serious thinko I made in revision 1.60 of this file.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13106 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-22 14:59:40 +00:00
Chris Lattner
1363e85df7 Implement a todo, rewriting all possible scev expressions inside of the
loop.  This eliminates the extra add from the previous case, but it's
not clear that this will be a performance win overall.  Tommorows test
results will tell. :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13103 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-21 23:36:08 +00:00
Chris Lattner
4e5f03602c This code really wants to iterate over the OPERANDS of an instruction, not
over its USES.  If it's dead it doesn't have any uses!  :)

Thanks to the fabulous and mysterious Bill Wendling for pointing this out.  :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13102 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-21 22:29:37 +00:00
Chris Lattner
5d461d20ae Implement a fixme. The helps loops that have induction variables of different
types in them.  Instead of creating an induction variable for all types, it
creates a single induction variable and casts to the other sizes.  This generates
this code:

no_exit:                ; preds = %entry, %no_exit
        %indvar = phi uint [ %indvar.next, %no_exit ], [ 0, %entry ]            ; <uint> [#uses=4]
***     %j.0.0 = cast uint %indvar to short             ; <short> [#uses=1]
        %indvar = cast uint %indvar to int              ; <int> [#uses=1]
        %tmp.7 = getelementptr short* %P, uint %indvar          ; <short*> [#uses=1]
        store short %j.0.0, short* %tmp.7
        %inc.0 = add int %indvar, 1             ; <int> [#uses=2]
        %tmp.2 = setlt int %inc.0, %N           ; <bool> [#uses=1]
        %indvar.next = add uint %indvar, 1              ; <uint> [#uses=1]
        br bool %tmp.2, label %no_exit, label %loopexit

instead of:

no_exit:                ; preds = %entry, %no_exit
        %indvar = phi ushort [ %indvar.next, %no_exit ], [ 0, %entry ]          ; <ushort> [#uses=2]
***     %indvar = phi uint [ %indvar.next, %no_exit ], [ 0, %entry ]            ; <uint> [#uses=3]
        %indvar = cast uint %indvar to int              ; <int> [#uses=1]
        %indvar = cast ushort %indvar to short          ; <short> [#uses=1]
        %tmp.7 = getelementptr short* %P, uint %indvar          ; <short*> [#uses=1]
        store short %indvar, short* %tmp.7
        %inc.0 = add int %indvar, 1             ; <int> [#uses=2]
        %tmp.2 = setlt int %inc.0, %N           ; <bool> [#uses=1]
        %indvar.next = add uint %indvar, 1
***     %indvar.next = add ushort %indvar, 1
        br bool %tmp.2, label %no_exit, label %loopexit

This is an improvement in register pressure, but probably doesn't happen that
often.

The more important fix will be to get rid of the redundant add.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13101 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-21 22:22:01 +00:00
Chris Lattner
c99acc3709 Fix PR325
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13081 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-20 20:26:03 +00:00
Chris Lattner
18f16094c2 Initial checkin of a simple loop unswitching pass. It still needs work,
but it's a start, and seems to do it's basic job.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13068 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-19 18:07:02 +00:00
Chris Lattner
5864aebe92 Add #include
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13057 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-19 03:01:23 +00:00
Chris Lattner
3280f7bd55 Move isLoopInvariant to the Loop class
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13051 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-18 22:46:08 +00:00
Chris Lattner
5fa802fe27 Loop exit sets are no longer explicitly held, they are dynamically computed on demand.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13046 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-18 22:15:13 +00:00
Chris Lattner
f1ab4b4eac Change the ExitBlocks list from being explicitly contained in the Loop
structure to being dynamically computed on demand.  This makes updating
loop information MUCH easier.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13045 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-18 22:14:10 +00:00
Chris Lattner
e3a55865bb Reduce the unrolling limit
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13040 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-18 18:06:14 +00:00
Chris Lattner
cc43909bb6 If the preheader of the loop was the entry block of the function, make sure
that the exit block of the loop becomes the new entry block of the function.

This was causing a verifier assertion on 252.eon.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13039 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-18 17:38:42 +00:00
Chris Lattner
998f44f859 Be much more careful about how we update instructions outside of the loop
using instructions inside of the loop.  This should fix the MishaTest failure
from last night.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13038 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-18 17:32:39 +00:00
Chris Lattner
50ca0a195a After unrolling our single basic block loop, fold it into the preheader and exit
block.  The primary motivation for doing this is that we can now unroll nested loops.

This makes a pretty big difference in some cases.  For example, in 183.equake,
we are now beating the native compiler with the CBE, and we are a lot closer
with LLC.

I'm now going to play around a bit with the unroll factor and see what effect
it really has.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13034 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-18 06:27:43 +00:00
Chris Lattner
9c2cc4626b Fix a bug: this does not preserve the CFG!
While we're at it, add support for updating loop information correctly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13033 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-18 05:38:37 +00:00
Chris Lattner
83bf2880c3 Initial checkin of a simple loop unroller. This pass is extremely basic and
limited.  Even in it's extremely simple state (it can only *fully* unroll single
basic block loops that execute a constant number of times), it already helps improve
performance a LOT on some benchmarks, particularly with the native code generators.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13028 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-18 05:20:17 +00:00
Chris Lattner
3c85eef81a Make the tail duplication threshold accessible from the command line instead of hardcoded
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13025 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-18 00:52:43 +00:00
Chris Lattner
20aa098ba6 If the loop executes a constant number of times, try a bit harder to replace
exit values.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13018 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-17 18:44:09 +00:00
Chris Lattner
4f1134e51a Fix a HUGE pessimization on X86. The indvars pass was taking this
(familiar) function:

int _strlen(const char *str) {
    int len = 0;
    while (*str++) len++;
    return len;
}

And transforming it to use a ulong induction variable, because the type of
the pointer index was left as a constant long.  This is obviously very bad.

The fix is to shrink long constants in getelementptr instructions to intptr_t,
making the indvars pass insert a uint induction variable, which is much more
efficient.

Here's the before code for this function:

int %_strlen(sbyte* %str) {
entry:
        %tmp.13 = load sbyte* %str              ; <sbyte> [#uses=1]
        %tmp.24 = seteq sbyte %tmp.13, 0                ; <bool> [#uses=1]
        br bool %tmp.24, label %loopexit, label %no_exit

no_exit:                ; preds = %entry, %no_exit
***     %indvar = phi uint [ %indvar.next, %no_exit ], [ 0, %entry ]            ; <uint> [#uses=2]
***     %indvar = phi ulong [ %indvar.next, %no_exit ], [ 0, %entry ]           ; <ulong> [#uses=2]
        %indvar1 = cast ulong %indvar to uint           ; <uint> [#uses=1]
        %inc.02.sum = add uint %indvar1, 1              ; <uint> [#uses=1]
        %inc.0.0 = getelementptr sbyte* %str, uint %inc.02.sum          ; <sbyte*> [#uses=1]
        %tmp.1 = load sbyte* %inc.0.0           ; <sbyte> [#uses=1]
        %tmp.2 = seteq sbyte %tmp.1, 0          ; <bool> [#uses=1]
        %indvar.next = add ulong %indvar, 1             ; <ulong> [#uses=1]
        %indvar.next = add uint %indvar, 1              ; <uint> [#uses=1]
        br bool %tmp.2, label %loopexit.loopexit, label %no_exit

loopexit.loopexit:              ; preds = %no_exit
        %indvar = cast uint %indvar to int              ; <int> [#uses=1]
        %inc.1 = add int %indvar, 1             ; <int> [#uses=1]
        ret int %inc.1

loopexit:               ; preds = %entry
        ret int 0
}


Here's the after code:

int %_strlen(sbyte* %str) {
entry:
        %inc.02 = getelementptr sbyte* %str, uint 1             ; <sbyte*> [#uses=1]
        %tmp.13 = load sbyte* %str              ; <sbyte> [#uses=1]
        %tmp.24 = seteq sbyte %tmp.13, 0                ; <bool> [#uses=1]
        br bool %tmp.24, label %loopexit, label %no_exit

no_exit:                ; preds = %entry, %no_exit
***     %indvar = phi uint [ %indvar.next, %no_exit ], [ 0, %entry ]            ; <uint> [#uses=3]
        %indvar = cast uint %indvar to int              ; <int> [#uses=1]
        %inc.0.0 = getelementptr sbyte* %inc.02, uint %indvar           ; <sbyte*> [#uses=1]
        %inc.1 = add int %indvar, 1             ; <int> [#uses=1]
        %tmp.1 = load sbyte* %inc.0.0           ; <sbyte> [#uses=1]
        %tmp.2 = seteq sbyte %tmp.1, 0          ; <bool> [#uses=1]
        %indvar.next = add uint %indvar, 1              ; <uint> [#uses=1]
        br bool %tmp.2, label %loopexit, label %no_exit

loopexit:               ; preds = %entry, %no_exit
        %len.0.1 = phi int [ 0, %entry ], [ %inc.1, %no_exit ]          ; <int> [#uses=1]
        ret int %len.0.1
}


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13016 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-17 18:16:10 +00:00
Chris Lattner
f50af088f1 Even if there are not any induction variables in the loop, if we can compute
the trip count for the loop, insert one so that we can canonicalize the exit
condition.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13015 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-17 18:08:33 +00:00
Chris Lattner
657253119e Fix some really nasty dominance bugs that were exposed by my patch to
make the verifier more strict.  This fixes building zlib


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13002 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-16 18:08:07 +00:00
Chris Lattner
006118fe8c Fix some of the strange CBE-only failures that happened last night.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12980 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-16 06:03:17 +00:00
Chris Lattner
d244057a48 Fix a bug in the previous checkin: if the exit block is not the same as
the back-edge block, we must check the preincremented value.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12968 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-15 20:26:22 +00:00
Chris Lattner
59fdaeeae8 Change the canonical induction variable that we insert.
Instead of producing code like this:

Loop:
  X = phi 0, X2
  ...

  X2 = X + 1
  if (X != N-1) goto Loop

We now generate code that looks like this:

Loop:
  X = phi 0, X2
  ...

  X2 = X + 1
  if (X2 != N) goto Loop

This has two big advantages:
  1. The trip count of the loop is now explicit in the code, allowing
     the direct implementation of Loop::getTripCount()
  2. This reduces register pressure in the loop, and allows X and X2 to be
     put into the same register.

As a consequence of the second point, the code we generate for loops went
from:

.LBB2:  # no_exit.1
	...
        mov %EDI, %ESI
        inc %EDI
        cmp %ESI, 2
        mov %ESI, %EDI
        jne .LBB2 # PC rel: no_exit.1

To:

.LBB2:  # no_exit.1
	...
        inc %ESI
        cmp %ESI, 3
        jne .LBB2 # PC rel: no_exit.1

... which has two fewer moves, and uses one less register.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12961 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-15 15:21:43 +00:00
Chris Lattner
d9955aaa61 ADd a trivial instcombine: load null -> null
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12940 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-14 03:28:36 +00:00
Chris Lattner
58b7b08ad7 Add SCCP support for constant folding calls, implementing:
test/Regression/Transforms/SCCP/calltest.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12921 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-13 19:43:54 +00:00
Chris Lattner
4647b7cd69 Constant propagation should remove the dead instructions
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12917 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-13 19:28:20 +00:00
Chris Lattner
1708d12916 Add support for removing invoke instructions
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12858 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-12 05:15:13 +00:00